Improvement in tension devices for sewing-machines



V 2Sheets--Sheet1a G. STA'CKPOLE.

Improvement ih Tension Devices for Sewing-Machines.

N 129,761". I Patented July 23,1872.

I 2 S heets--Sheet2 I G. STACKPOLE.

l mprovemenhin Tension Devices for Sewing-Machines.

I No. 129,761. Patented July 23,1322.

the thread just right; and for given sizes of thread a certain-sizedneedle should always be thereof so that when in a certain position it'used with such thread, and also the number of machine should be providedwith an index for lation shown in Figs. 1, 2, and 3. 'In Figs. 1,

vice are mounted in a frame secured to the spindle a is secured at oneend to an upright,

ummsmas;

A'IEN .GREnivLEAFfsrAcKPoLE,on ELIZABETH, NEW JERSEY.

IMPROVEMENTINLITEINSION DEVICES OR SEWING-MACHINES.

M Specification forming partof Letters Patent No. 129,261, dated July23, 1872.

srnomrcnrroiv.

Beitknown that I, GREENLEAF STAoKPoLE, of Elizabeth, in Union county, inthe State of New Jersey, have made an Invention in Sewing-Machines, ofwhich the following is a description, and in the drawing forming part ofthis application like letters indicate corresponding parts.

In sewing-machines the spool of thread is commonlyplaced in a verticalposition over a pin and made to rest on one of its heads, or else it isslipped over a horizontal spindle, and

spool varies and necessitates a change of tenmom or causes unevensewing. Whencoma little experimentally to get the tension on used, andeach thread to do best sewing should in the cloth form a certain numberof stitches to the inch. First-class operators understand these properrelations between needle, thread, and stitch; but with others it is aquestion of experiment each day, and when this proper condition is notreached the sewing is not as perfect as it might be.

Myinvention relates to thread-tension mechanism and its object is toadapt all the parts will produce exactly the right tension forcertain-sized thread or silk; and, further, it will then indicatethe-.proper-sized needle; to be stitches to an inch. The feeding deviceof the this purpose, and for convenience it should beplaced plainly inview of the operator.

Figure 1 is a side view of my invention. Fig. 2 is a top view. Fig. 3 isa side sectional view.

On second page of the accompanying drawin g, which are modifications ofmy invention, the spool of thread is not shown in the modifications, butin each case it is to occupy the re- 2, and 3 on page 1, the spool andtension demachiue in'any suitable position. The spoolb, but made quicklyand easily removable therefrom. In this instance set-nuts c are shown,but instead the spindle maybe clamped in any suitable way to itssupport. The forward end of the spindle is provided with a cap or disk,(I, preferably'larger than the head 6 of the spool, and the spool-headrests against this cap or disk, and the thread passes continually aboutthis cap as it unwinds, but the spool remains stationary on its spindle.The tension mechanism is located in advance of the cap, and in Figs. 1,2, and 3, it consists of two smooth surfaces, f g--one or more somewhatelastic or capable of receding from the other, and the one designated byg is provided with a screw, h, to regulate its position with relation tothe other surface f, in order to produce the requisite frictional actionon the thread 2'. One of these surfaces might be a roller. This screwisprovided with or operates a pointer, 79, which, as the screw isturned, passes over certain figures on the dial 1. This dial isstationary, and is provided with numbers corresponding with numberscommonly used on spools of thread.

It is not actually necessary to indicate every such spool-number on thedial, because in some cases two sizes of thread may be used with aboutthe same tension and same-sized needle. When the operator has placed thespool of thread on its spindle he passes the thread between the fiictionsurfaces, and turns the screw until the pointer comes opposite thenumber indicated on the dial, and corresponding with the spool-number;and. when in this position the dial will also indicate adjacent to suchnumbertheproper-sizedneedle andlength of stitch or number to an inch,and the operator, when the needle and feed are right, can commencesewing at once and be certain of reaching the best possible result.

My invention may be carried out in various ways in connection with otherwell-known forms of tension devices commonly used in page 2, show thedial as applied to the long flat spring. Figs. 7 and 8, page 2, show theFFICE.

dial as applied to the screw-like device of the \Veed machine. In eachof these instances I have shown a registering apparatus in connectionwith these well-known forms of devices, and in each case I propose tohave the spool in the position shown in Fig. 1.

Claims.

Having described my invention, what I claim.is-

1. JIhe combination, with the spindle to support a spool and deliver athread therefrom without the spool turning thereon, of atension device,substantially as described, when provided with a regulating apparatus toindicate the amount of tension on different-sized threads; and I alsoclaim the said combination of the devices above enumerated when providedwith numbers to designate the size of needles and length of stitch to beused with certain-sized thread.

2. Also, I claim the combination, with a tension device, substantiallyas described, of a dial or regulating mechanism, or device to in-

